CN205429763U - Five looks photovoltaic inverter pre -assembling substation rooms - Google Patents

Abstract

The utility model discloses a five looks photovoltaic inverter pre -assembling substation rooms. This five looks photovoltaic inverter pre -assembling substation rooms includes five photovoltaic inverter, transformer, dc -to -ac converter room and transformer room, and wherein this photovoltaic inverter sets up in the dc -to -ac converter indoorly, and the transformer sets up in the transformer room to and connect through the copper bar between dc -to -ac converter room and the transformer room. Five looks photovoltaic inverter include direct current breaker, DCDC converter, five looks contravariant bridges, five phase filters and alternating current circuit ware, and wherein, direct current breaker's output is connected with the input electricity of DCDC converter, and the output of DCDC converter is connected with the input of five looks contravariant bridges electricity, and the output and the five phase filters electricity of five looks contravariant bridges are connected to and five phase filters are connected with alternating current circuit ware electricity. The utility model discloses a pre -assembling substation room has that the linear modulation scope is big, the advantage that harmonic component is low in DC power supply high -usage and output voltage and the electric current.

Description

Five phase photovoltaic DC-to-AC converters pre-assembled substation room

Technical field

The utility model relates to field of photovoltaic power generation, is specifically related to a kind of five phase photovoltaic DC-to-AC converter pre-assembled substation room.

Background technology

Solar energy has the advantages such as safe and clean and resource generality, it is possible to becomes and substitutes the regenerative resource that fossil energy is main.Solar energy power generating in its developmental research, market development and industrialized manufacture technology already as the focus of world community keen competition.

Ground light photovoltaic generating system is typically to be made up of photovoltaic array, header box, photovoltaic DC-to-AC converter, box-type substation and booster stations five part.When this system is applied to photovoltaic generating system, there is the defects such as integration degree is low, equipment failure rate is high.The pre-assembled substation room combined along with the large-scale development of photovoltaic industry, photovoltaic DC-to-AC converter and box-type substation has become the trend of modern photovoltaic industry era development.

But, traditional pre-assembled substation room still has the shortcomings such as capacity is little, transformation efficiency is low in actual moving process, and this has become as restriction photovoltaic plant to intelligent, the bottleneck of modular development.Simultaneously as the extensively application of power electronic devices makes electric power system no longer be limited by traditional three phase supply number of phases, multiphase system (number of phases is more than the system of three-phase) gets the attention.Multiphase system improves the power output of whole system, is particularly suitable for the fields such as application and electric locomotive traction, marine electric power propulsion, Aero-Space.

The defect in current substation room is in particular in:

First, traditional pre-assembled substation room requires that inverter must be debugged by commissioning staff at device interior, threatens the personal safety of personnel；

Secondly, secondary control system uses singlechip technology or DSP to control technology, and its master control borad is affected obvious by factors such as layout structure, mask-making technology and device qualities, poor anti jamming capability, is difficult to extension, and accident rate is higher, strong to surrounding environment dependence, the construction cycle is long.

Again, the defect of three phase inverter bridge inversion: 1., inverter is when being converted to industrial-frequency alternating current by direct current, and harmonic content is high, and conversion efficiency is low；2., the capacity of inverter little, be unsuitable for photovoltaic array extensive, jumbo.

Utility model content

The purpose of this utility model is to provide a kind of five phase photovoltaic DC-to-AC converter pre-assembled substation room and control methods thereof, thus solves above-mentioned problems of the prior art.

In order to solve the problems referred to above, according to an aspect of the present utility model, provide a kind of five phase photovoltaic DC-to-AC converter pre-assembled substation room, described five phase photovoltaic DC-to-AC converter pre-assembled substation room includes five photovoltaic DC-to-AC converters, transformer, inverter room and transformer room, it is indoor that wherein said photovoltaic DC-to-AC converter is arranged at described inverter, described transformer is arranged in described transformer room, and is connected by copper bar between described inverter room and described transformer room；And described five phase photovoltaic DC-to-AC converters include dc circuit breaker, DC/DC converter, five phase inverter bridge, five phase filters and AC circuit breaker, wherein, the output of described dc circuit breaker electrically connects with the input of described DC/DC converter, the output of described DC/DC converter electrically connects with the input of described five phase inverter bridge, the output of described five phase inverter bridge electrically connects with described five phase filters, and described five phase filters electrically connect with described AC circuit breaker.

It is preferred that described five phase photovoltaic DC-to-AC converters have 1/4 working method and 2/3 working method；Wherein

Described 1/4 working method refers at a time, and the upper brachium pontis of described five phase inverter bridge has one to be conducted, and lower brachium pontis has four to be conducted, or the upper brachium pontis of described five phase inverter bridge has four to be conducted, and lower brachium pontis has one to be conducted；And

Described 2/3 working method refers at a time, and the upper brachium pontis of described five phase inverter bridge has two to be conducted, and lower brachium pontis has three to be conducted, or the upper brachium pontis of described five phase inverter bridge has three to be conducted, and lower brachium pontis has two to be conducted.

It is preferred that in described 1/4 working method and 2/3 working method, upper brachium pontis conducting mutually adjacent, and the conducting of lower brachium pontis is mutually adjacent.

Preferably, described five phase photovoltaic DC-to-AC converters also include SPWM module and PMU module, wherein said SPWM module is connect with described five phase inversion bridgings by control line, described PMU module is connected with described SPWM module by holding wire, during operation, described PMU module sends instructions to described SPWM module, and described SPWM module controls the IGBT pipe break-make of five phase inverter bridge, thus obtains desired voltage signal.

It is preferred that described PMU module and SPWM module electrically connect with power supply.

It is preferred that described SPWM module be provided with perform procedure below circuit:

(1) switching equation of five phase photovoltaic DC-to-AC converters is set up: S=[S_a, S_b, S_c, S_d, S_e], wherein, S_k=1 represents switch conduction, lower switch OFF on photovoltaic DC-to-AC converter a phase brachium pontis, S_k=0 represents upper switch OFF, lower switch conduction, wherein k=a, b, c, d, or e；

(2) the pole tension equation of five phase photovoltaic DC-to-AC converters: u is set up_k0=S_kU_d-U_d/2；

(3) the voltage vector equation of five phase photovoltaic DC-to-AC converters is set up:

(4) obtaining 32 voltage vectors of five phase photovoltaic DC-to-AC converters, these 32 voltage vectors include big vector U_Li, i is >=1 and the integer of≤10, middle vector U_Mj, j is >=1 and the integer of≤10, small vector U_Sn, n is >=1 and the integer of≤10, and two zero vector U₀, wherein these 32 voltage vectors are scattered in 10 sectors, and each sector includes two big vectors, two middle vectors, two small vectors and a zero vector；

(5) synthesized reference voltage U_ref: set reference voltage U_refIt is positioned at kth sector, selects U_L(k+1)、U_Mk、U_M(k+2)And a zero vector carrys out synthesized reference voltage U_ref；

(6) voltage U is obtained_L(k+1)、U_Mk、U_M(k+2)And U₀Action time.

Preferably, described five phase photovoltaic DC-to-AC converters also include direct current EMC wave filter, described direct current EMC wave filter is arranged between described dc circuit breaker and described DC/DC converter, the wherein said input of direct current EMC wave filter electrically connects with the output of described dc circuit breaker, and the output of described direct current EMC wave filter electrically connects with the input of described DC/DC converter.

Preferably, described five phase photovoltaic DC-to-AC converters also include exchanging EMC wave filter, described exchange EMC wave filter is arranged between described five phase filters and described AC circuit breaker, the wherein said input of exchange EMC wave filter electrically connects with the output of described five phase filters, and the output of described exchange EMC wave filter electrically connects with the input of described AC circuit breaker.

According to another aspect of the present utility model, additionally provide the control method in a kind of five phase photovoltaic DC-to-AC converter pre-assembled substation room, said method comprising the steps of:

(1) switching equation of five phase photovoltaic DC-to-AC converters is set up: S=[S_a, S_b, S_c, S_d, S_e], wherein, S_k=1 represents switch conduction on photovoltaic DC-to-AC converter a phase brachium pontis, lower switch OFF；S_a=0 represents upper switch OFF, lower switch conduction, k=a, b, c, d or e；

(2) the pole tension equation of five phase photovoltaic DC-to-AC converters: u is set up_k0=S_kU_d-U_d/2；

(3) the voltage vector equation of five phase photovoltaic DC-to-AC converters is set up:

(4) obtaining 32 voltage vectors of five phase photovoltaic DC-to-AC converters, these 32 voltage vectors include big vector U_Li, i is >=1 and the integer of≤10, middle vector U_Mj, j is >=1 and the integer of≤10, small vector U_Sn, n is >=1 and the integer of≤10, and two zero vector U₀, wherein these 32 voltage vectors are scattered in 10 sectors, and each sector includes two big vectors, two middle vectors, two small vectors and a zero vector；

(5) synthesized reference voltage U_ref: set reference voltage U_refIt is positioned at kth sector, selects U_L(k+1)、U_Mk、U_M(k+2)And a zero vector U₀Carry out synthesized reference voltage U_ref；

(6) voltage U is obtained_L(k+1)、U_Mk、U_M(k+2)And U₀Action time.

It is preferred that obtain voltage U by following steps_L(k+1)、U_Mk、U_M(k+2)And U₀Action time:

It is located at switch periods T_sThe action time of interior kth vector is T_k, set up vector balancing equation in kth sector:

$\left\{\begin{array}{c}{T}_s{U}_{ref}=T_{L(k+1)}{U}_{L(k+1)}+T_{Mk}{U}_{MK}+T_{M(k+2)}{U}_{M(K+2)}\\ T_s=T_{L(k+1)}+T_{Mk}+T_{M(k+2)}+T_0\end{array}\right.$

Thus obtain T_L(k+1)、T_(M+2)k、T_MkAnd T₀。

It is preferred that voltage U_L(k+1)、U_Mk、U_M(k+2)And U₀Sequence of operation be: U_Mk→U_L(k+1)→U_M(k+2)→U₀→U_M(k+2)→U_L(k+1)→U_Mk。

It is preferred that as described U_refWhen being positioned at first sector, voltage UM₁、UL₂、UM₃And U₀Sequence of operation be UM₁(10000)→UL₂(11000)→UM₃(01000)→U₀(00000)→UM₃(01000)→UL₂(11000)→UM₁(10000)。

Five phase photovoltaic DC-to-AC converters of the present utility model possess following advantage:

(1) five phase control system is bigger than the modulation index of conventional three-phase system, and therefore the linear modulation scope of five phase photovoltaic DC-to-AC converters is bigger, and dc source utilization rate is higher；

Harmonic component in (2) five phase photovoltaic DC-to-AC converter output voltages and electric current reduces；

(3) when the phase in five phases or a few phase break down, by suitable control, photovoltaic DC-to-AC converter still can be by energetic start up and operation, and system reliability is high；

(4) transformation efficiency and the grid connection capacity of photovoltaic DC-to-AC converter are improved to greatest extent.

Accompanying drawing explanation

Fig. 1 is the topology diagram in the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room；

Fig. 2 is the side schematic view in the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room；

Fig. 3 is the floor map in the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room；

Fig. 4 is the topology diagram of the utility model five phase photovoltaic DC-to-AC converter；

Fig. 5 is the space voltage vector figure of the utility model five phase photovoltaic DC-to-AC converter, and wherein small voltage vector is not shown；And

Fig. 6 is the PWM waveform figure of the first sector obtained by five phase photovoltaic DC-to-AC converter control methods of the present utility model.

Detailed description of the invention

Below with reference to accompanying drawing, preferred embodiment of the present utility model is described in detail, in order to become apparent from understanding the purpose of this utility model, feature and advantage.It should be understood that embodiment shown in the drawings is not the restriction to the utility model scope, and simply to illustrate that the connotation of technical solutions of the utility model.

Term explanation

Substation room: electrical equipment photovoltaic DC-to-AC converter and box-type substation become one, the DC conversion that photovoltaic arrays is produced by this system is alternating current, and completes supply electrical network use of once boosting.

Photovoltaic DC-to-AC converter: inverter is to connect resistance capacitance by power electronic devices (MOSFET, IGBT etc.), the break-make of device is controlled in the way of pulse width modulation, the direct current that header box transmission is come is transformed into alternating current, complete the MPPT maximum power point tracking (MPPT) of photovoltaic module, it is ensured that Based Intelligent Control and anti-islanding effect etc. simultaneously.

DC/DC converter: realize the boosting to photovoltaic array, complete the tracking (MPPT) to photovoltaic array Maximum Power Output simultaneously.

Inverter bridge: use full bridge structure, direct current is converted into industrial-frequency alternating current.

Fig. 1 is the system schematic in the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room, the side schematic view in Fig. 2 the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room.Fig. 3 is the floor map in the utility model five phase photovoltaic DC-to-AC converter pre-assembled substation room.As shown in Figures 1 to 3, five phase photovoltaic DC-to-AC converters pre-assembled substation room includes two photovoltaic DC-to-AC converters 100, transformer 200, inverter room 100A, transformer room 9 and hyperbaric chamber 11, and wherein two photovoltaic DC-to-AC converters 100 are electrically connected with transformer 200 by wire.

Five phase photovoltaic DC-to-AC converters 100 are arranged in the 100A of inverter room, and transformer 200 is arranged in transformer room 9, and the relay (not shown) of arrester, lightning-arrest counter and detection power transformer interior fault is arranged in hyperbaric chamber 11.The direct current transmitted from photovoltaic module becomes alternating current after five phase light inverters 100 and flows to transformer 200, it is transferred to after boosting in transformer 200 in hyperbaric chamber 11, and be connected with the wire being connected to electrical network by terminal in hyperbaric chamber 11, thus the electric current after inverter 100 carries out commutation is connected to the grid.

As shown in figures 2-3, inverter room 100A includes that direct current converges line cabinet 1, inverter bridge room 4, filter chamber 5 and exchange and converges line cabinet 7, wherein dc circuit breaker 10 be arranged at that direct current converges in line cabinet 1, DC/DC converter 20 is arranged at five phase inverter bridge 30 in inverter bridge room 4, five phase filters 40 be arranged at filter chamber 5 in and AC circuit breaker 50 be arranged at exchange and converge in line cabinet 7.

Direct current remittance line cabinet 1 offers window 1A, inverter bridge room 4 offers window 4A, filter chamber 5 offers window 5A, exchange remittance line cabinet 7 offers window 7A, hyperbaric chamber 11 offers window 11A, can be operated dc circuit breaker 10, DC/DC converter 20, five phase inverter bridge 30, five phase filter 40 and AC circuit breaker 50 respectively by window 1A, 4A, 5A and 7A.

In direct current converges line cabinet 1, it is provided with heat abstractor 1B, in inverter bridge room 4, is provided with heat abstractor 4B, in filter chamber 5, be provided with heat abstractor 5B, and be provided with heat abstractor 7B in exchange converges line cabinet 7.Effect by heat abstractor 1B, 4B, 5B and 7B, it is possible to the temperature preventing direct current remittance line cabinet 1, inverter bridge room 4, filter chamber 5 and exchange remittance line cabinet 7 is too high.

As shown in Figure 4, five phase photovoltaic DC-to-AC converters 100 of the present utility model generally include dc circuit breaker 10, DC/DC converter 20, five phase inverter bridge 30, five phase filters 40 and AC circuit breaker 50, wherein, the output of dc circuit breaker 10 electrically connects with the input of DC/DC converter 20, the output of DC/DC converter 20 and the input electrical connection of five phase inverter bridge 30, the output of five phase inverter bridge 30 and the input electrical connection of five phase filters 40, the output of five phase filters 40 electrically connects with the input of AC circuit breaker 50, wherein, DC/DC converter realizes the raising to photovoltaic array output voltage, complete the tracking (MPPT) of maximum power point.

Five phase inverter bridge 30 include 10 IGBT switching tube: S₁～S₁₀, five phase filters 40 use RLC mode filter, and internal resistance that R represents wave filter and the loss of voltage caused by every phase brachium pontis upper and lower interlocking dead band, L represents grid-connected wave filter.

As shown in Figure 4, five phase photovoltaic DC-to-AC converters 100 of the present utility model also include SPWM module 60 and PMU module 70, SPWM module 60 by control line 61 respectively with 10 IGBT switching tube S of five phase inverter bridge 20₁～S₁₀Connect, thus IGBT pipe S can be controlled by SPWM module 60₁～S₁₀Conducting and disconnection, PMU module 70 is connected with SPWM module 60 by holding wire 71, instructs such that it is able to send to SPWM module 60.

SPWM module 60 and PMU module 70 is connected with power supply by wire the most respectively, and arrow 62,63 represents signal wave and carrier wave respectively, signal wave refers to using scaled for the waveform intentionally got as modulated signal, in the utility model, this modulated signal is sinusoidal wave, and carrier wave refers to accept the signal of modulation.

During operation, PMU module 70 sends instructions to SPWM module 60, and SPWM module 60 controls the IGBT pipe break-make of five phase inverter bridge, thus obtains desired voltage signal.

When carrier signal reaches SPWM module 60, this carrier signal is reached PMU module 70 by holding wire by SPWM module 60, PMU module 70 issues instructions to SPWM module 60, and SPWM module 60 performs to calculate comparing function, and is controlled 10 IGBT pipe pipe S of five phase inverter bridge 20 by control line₁～S₁₀Break-make, thus obtain desired voltage signal.

In another embodiment of the present utility model, five phase photovoltaic DC-to-AC converters 100 also include direct current EMC wave filter, direct current EMC wave filter is arranged between dc circuit breaker 10 and DC/DC converter, the input of direct current EMC wave filter electrically connects with the output of dc circuit breaker 10, the output of direct current EMC wave filter electrically connects with the input of DC/DC converter, and direct current EMC wave filter realizes filtering the effect of electromagnetism harmonic wave.

In another embodiment of the present utility model, five phase photovoltaic DC-to-AC converters 100 also include exchanging EMC wave filter, exchange EMC wave filter is arranged between five phase filters 40 and AC circuit breaker 50, the input of exchange EMC wave filter and the output electrical connection of five phase filters 40, the output of exchange EMC wave filter electrically connects with the input of AC circuit breaker 50, and exchange EMC wave filter realizes filtering the effect of electromagnetism harmonic wave.

Five phase photovoltaic DC-to-AC converter topological structures of the present utility model are simple, have the advantage not limited by amount of capacity.But control mode is the most relative complex, introduce the control method of the utility model five phase photovoltaic DC-to-AC converter in detail below.

If the switch function of five phase photovoltaic DC-to-AC converters is

S=[S_a, S_b, S_c, S_d, S_e](1)

If S_a=1, then it represents that switch conduction on photovoltaic DC-to-AC converter a phase brachium pontis, lower switch OFF, output point is U to the voltage (pole tension) of power center's point O_d/2；

If S_a=0, then switch OFF on a phase brachium pontis, lower switch conduction, output stage voltage is-U_d/ 2, other each switch functions are same.

Now, polyphase inverter output stage voltage switch function is expressed as

u_k0=S_kU_d-U_d/2(2)

Five phase photovoltaic DC-to-AC converter output line voltages can be expressed as

$\left[\begin{array}{c}{u}_{ab}\\ u_{bc}\\ u_{cd}\\ u_{de}\\ u_{ea}\end{array}\right]=U_d\left[\begin{array}{ccccc}1& -1& 0& 0& 0\\ 0& 1& -1& 0& 0\\ 0& 0& 1& -1& 0\\ 0& 0& 0& 1& -1\\ -1& 0& 0& 0& 1\end{array}\right]\left[\begin{array}{c}{S}_a\\ S_b\\ S_c\\ S_d\\ S_e\end{array}\right]---\left(3\right)$

Five phase photovoltaic DC-to-AC converter output phase voltages can be expressed as

$\left[\begin{array}{c}{u}_{aN}\\ u_{bN}\\ u_{cN}\\ u_{dN}\\ u_{eN}\end{array}\right]=\frac{U_d}{5}\left[\begin{array}{ccccc}4& -1& -1& -1& -1\\ -1& 4& -1& -1& -1\\ -1& -1& 4& -1& -1\\ -1& -1& -1& 4& -1\\ -1& -1& -1& -1& 4\end{array}\right]\left[\begin{array}{c}{S}_a\\ S_b\\ S_c\\ S_d\\ S_e\end{array}\right]---\left(4\right)$

Therefore, space vector of voltage equation is

$U_k=u_{aN}+e^{j\frac{2\mathrm{\π}}{5n}}{u}_{bN}+e^{j\frac{4\mathrm{\π}}{5}}{u}_{cN}+e^{j\frac{6\mathrm{\π}}{5}}{u}_{dN}+e^{j\frac{8\mathrm{\π}}{5}}{u}_{eN}---\left(5\right)$

Formula (4) is brought into formula (5) obtain,

$U_k=\frac{2}{5}{U}_d\[S_a+e^{j\frac{2\mathrm{\π}}{5}}{S}_b+e^{j\frac{4\mathrm{\π}}{5}}{S}_c+e^{j\frac{6\mathrm{\π}}{5}}{S}_d+e^{j\frac{8\mathrm{\π}}{5}}{S}_e\]---\left(6\right)$

According to above-mentioned definition, 32 different voltage vectors can be there are through calculating.Each 10 of large, medium and small vector, additionally has 2 zero vectors, and space voltage vector figure is as shown in Figure 5.They are divided into 10 sectors space.Wherein, shown in big or middle vector magnitude expression formula such as formula (7) formula (8).

$U_L=\frac{2}{5}{U}_d\[1+2cos\left(\frac{2}{5}\mathrm{\π}\right)\]---\left(7\right)$

$U_M=\frac{2}{5}{U}_d---\left(8\right)$

In figure, 5 binary systems corresponding to each voltage vector are the switch functions of this vector.Wherein, the different operating state of effective vector of large, medium and small 3 kinds of amplitudes corresponding five phase photovoltaic DC-to-AC converters respectively, i.e. 1/4 working method, 2/3 working method and pseudo-2/3 working method.So-called 2/3 working method refers at a time, and on photovoltaic DC-to-AC converter, brachium pontis has two to be conducted, and lower brachium pontis has three to be conducted or vice versa, and upper brachium pontis (or lower brachium pontis) turn on mutually adjacent, the voltage vector that can make synthesis is maximum.1/4 working method is similar to therewith.The three-phase that pseudo-2/3 working method is simultaneously turned on by brachium pontis thereon (or lower brachium pontis) is the most adjacent, the phase that middle existence is not turned on, and for preventing the Excitation interference caused between phase and phase, therefore should avoid using.

The utility model uses 2/3 working method and 1/4 working method Comprehensive Control, so that the waveform of output is the most steady.Under this control method, use a big vector, one zero vector of two middle vectors that the reference voltage in sector is synthesized.

Illustrate as a example by first sector below, select UM₁(10000)、UL₂(11000)、UM₃And U (01000)₀(00000) vector is to reference voltage U_refSynthesize.Sequence of operation in the first sector is UM₁(10000)→UL₂(11000)→UM₃(01000)→U₀(00000)→UM₃(01000)→UL₂(11000)→UM₁(10000)。

It is located at switch periods T_sThe action time of interior kth vector is T_k, then in each sector, vector balancing equation is:

$\left\{\begin{array}{c}{T}_s{U}_{ref}=T_{L(k+1)}{U}_{L(k+1)}+T_{Mk}{U}_{MK}+T_{M(k+2)}{U}_{M(K+2)}\\ T_s=T_{L(k+1)}+T_{Mk}+T_{M(k+2)}+T_0\end{array}\right.---\left(1\right)$

According to formula (1), time variable T can be obtained_L(k+1)、T_(M+2)k、T_MkAnd T₀Value, wherein, the PWM waveform under which is shown in Fig. 6.

By above analysis, the control method of the utility model five phase photovoltaic DC-to-AC converter of the present utility model mainly comprises the steps that

(1) switching equation of five phase photovoltaic DC-to-AC converters is set up: S=[S_a, S_b, S_c, S_d, S_e], wherein, S_k=1 represents switch conduction on photovoltaic DC-to-AC converter a phase brachium pontis, lower switch OFF；S_a=0 represents upper switch OFF, lower switch conduction, k=a, b, c, d or e；

(2) the pole tension equation of five phase photovoltaic DC-to-AC converters: u is set up_k0=S_kU_d-U_d/2；

(3) the voltage vector equation of five phase photovoltaic DC-to-AC converters is set up:

(4) 32 voltage vectors of five phase photovoltaic DC-to-AC converters are obtained.

As in figure 2 it is shown, these 32 voltage vectors include big vector U_Li, i is >=1 and the integer of≤10, middle vector U_Mj, j is >=1 and the integer of≤10, small vector U_Sn(not shown), n is >=1 and the integer of≤10, and two zero vector U₀, wherein these 32 voltage vectors are scattered in 10 sectors, and each sector includes two big vectors, two middle vectors, two small vector (not shown) and a zero vector；

(5) synthesized reference voltage U_ref: set reference voltage U_refIt is positioned at kth sector, selects U_L(k+1)、U_Mk、U_M(k+2)And a zero vector U₀Carry out synthesized reference voltage U_ref；

(6) voltage U is obtained_L(k+1)、U_Mk、U_M(k+2)And U₀Action time:

It is located at switch periods T_sThe action time of interior kth vector is T_k, set up vector balancing equation in kth sector:

$\left\{\begin{array}{c}{T}_s{U}_{ref}=T_{L(k+1)}{U}_{L(k+1)}+T_{Mk}{U}_{MK}+T_{M(k+2)}{U}_{M(K+2)}\\ T_s=T_{L(k+1)}+T_{Mk}+T_{M(k+2)}+T_0\end{array}\right.$

Thus obtain T_L(k+1)、T_(M+2)k、T_MkAnd T₀。

Five phase photovoltaic DC-to-AC converters of the present utility model have the advantage that

(1) five phase control system is bigger than the modulation index of conventional three-phase system, and therefore the linear modulation scope of five phase photovoltaic DC-to-AC converters is bigger, and dc source utilization rate is higher；

Harmonic component in (2) five phase photovoltaic DC-to-AC converter output voltages and electric current reduces；

(3) when the phase in five phases or a few phase break down, by suitable control, photovoltaic DC-to-AC converter still can be by energetic start up and operation, and system reliability is high；

(4) improve transformation efficiency and the grid connection capacity of photovoltaic DC-to-AC converter to greatest extent, output waveform is the most steady simultaneously.

Below preferred embodiment of the present utility model has been described in detail, it is understood that after having read above-mentioned instruction content of the present utility model, the utility model can be made various changes or modifications by those skilled in the art.These equivalent form of values fall within the application appended claims limited range equally.

Claims (7)

1. a phase photovoltaic DC-to-AC converter pre-assembled substation room, it is characterised in that described five phase photovoltaic DC-to-AC converter pre-assembled substation room includes five photovoltaic DC-to-AC converters, transformer, inverter room and transformer room, wherein

It is indoor that described photovoltaic DC-to-AC converter is arranged at described inverter, and described transformer is arranged in described transformer room, and is connected by copper bar between described inverter room and described transformer room；And

Described five phase photovoltaic DC-to-AC converters include dc circuit breaker, DC/DC converter, five phase inverter bridge, five phase filters and AC circuit breaker, wherein, the output of described dc circuit breaker electrically connects with the input of described DC/DC converter, the output of described DC/DC converter electrically connects with the input of described five phase inverter bridge, the output of described five phase inverter bridge electrically connects with described five phase filters, and described five phase filters electrically connect with described AC circuit breaker.

Five phase photovoltaic DC-to-AC converter the most according to claim 1 pre-assembled substation room, it is characterised in that described five phase photovoltaic DC-to-AC converters have 1/4 working method and 2/3 working method；Wherein

Described 1/4 working method refers at a time, and the upper brachium pontis of described five phase inverter bridge has one to be conducted, and lower brachium pontis has four to be conducted, or the upper brachium pontis of described five phase inverter bridge has four to be conducted, and lower brachium pontis has one to be conducted；And

Described 2/3 working method refers at a time, and the upper brachium pontis of described five phase inverter bridge has two to be conducted, and lower brachium pontis has three to be conducted, or the upper brachium pontis of described five phase inverter bridge has three to be conducted, and lower brachium pontis has two to be conducted.

Five phase photovoltaic DC-to-AC converter the most according to claim 2 pre-assembled substation room, it is characterised in that in described 1/4 working method and 2/3 working method, upper brachium pontis conducting mutually adjacent, and lower brachium pontis conducting mutually adjacent.

Five phase photovoltaic DC-to-AC converter the most according to claim 1 pre-assembled substation room, it is characterized in that, described five phase photovoltaic DC-to-AC converters also include SPWM module and PMU module, wherein said SPWM module is connect with described five phase inversion bridgings by control line, described PMU module is connected with described SPWM module by holding wire, and during operation, described PMU module sends instructions to described SPWM module, described SPWM module controls the IGBT pipe break-make of five phase inverter bridge, thus obtains desired voltage signal.

Five phase photovoltaic DC-to-AC converter the most according to claim 4 pre-assembled substation room, it is characterised in that it is preferred that described PMU module and SPWM module electrically connect with power supply.

Five phase photovoltaic DC-to-AC converter the most according to claim 1 pre-assembled substation room, it is characterized in that, described five phase photovoltaic DC-to-AC converters also include direct current EMC wave filter, described direct current EMC wave filter is arranged between described dc circuit breaker and described DC/DC converter, the wherein said input of direct current EMC wave filter electrically connects with the output of described dc circuit breaker, and the output of described direct current EMC wave filter electrically connects with the input of described DC/DC converter.

Five phase photovoltaic DC-to-AC converter the most according to claim 1 pre-assembled substation room, it is characterized in that, described five phase photovoltaic DC-to-AC converters also include exchanging EMC wave filter, described exchange EMC wave filter is arranged between described five phase filters and described AC circuit breaker, the wherein said input of exchange EMC wave filter electrically connects with the output of described five phase filters, and the output of described exchange EMC wave filter electrically connects with the input of described AC circuit breaker.